表單位置和大小行爲

Question

我想將窗體放置在屏幕的左上角。

我試過this.Location = new Point(0,0)，但窗口位於（7,0） - 窗口頂部位於屏幕頂部，但左側距離屏幕邊緣7個像素。 我創造了新的WinForms應用程序進行測試和只添加以下代碼：

private void Form1_Load(object sender, EventArgs e) 
{ 
    Point p = new Point(0, 0); 

    WindowState = FormWindowState.Maximized; 
    Debug.WriteLine("\nMaximized"); 
    Debug.WriteLine("Location: " + Location); 
    Debug.WriteLine("Size: " + Size); 
    Debug.WriteLine("PointToScreen(0,0): " + PointToScreen(p)); 

    WindowState = FormWindowState.Normal; 
    Location = p;    
    Debug.WriteLine("\nNormal"); 
    Debug.WriteLine("Location: " + Location); 
    Debug.WriteLine("Size: " + Size); 
    Debug.WriteLine("PointToScreen(0,0): " + PointToScreen(p)); 

    Debug.Write("\nScreen.PrimaryScreen.WorkingArea: "); 
    Debug.WriteLine(Screen.PrimaryScreen.WorkingArea); 
} 

輸出是：

Maximized 
Location: {X=-8,Y=-8} 
Size: {Width=1936, Height=1056} 
PointToScreen(0,0): {X=0,Y=23} 

Normal 
Location: {X=0,Y=0} 
Size: {Width=300, Height=300} 
PointToScreen(0,0): {X=8,Y=31} 

Screen.PrimaryScreen.WorkingArea: {X=0,Y=0,Width=1920,Height=1040} 

爲什麼Location = new Point(0,0)不會在（0,0）位置的形式？ 這是由於我的系統上的東西？我有Win10和VS2015。任務欄在底部，我的桌面左側沒有任何東西。 爲了將它定位在（0,0）上，我實際上必須將它定位在（-7,0）上。此外，最大化形式的報告寬度比屏幕寬度大16個像素。我明白，由於窗口邊緣，標題欄等，客戶區域大小和窗體大小之間存在差異，但事實並非如此。當表格最大化時，沒有左右邊緣（客戶區寬度=桌面寬度），但表格寬度爲+ 16px。窗體四邊各有8px，但Y位置正確。爲什麼Y位置正確而X不是？

Answer 1

我想出了這個問題。

只需設置

this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;

和測試結果。對我來說是這樣的：

Maximized 
Location: {X=0,Y=0} 
Size: {Width=1280, Height=800} 
PointToScreen(0,0): {X=0,Y=0} 

Normal 
Location: {X=0,Y=0} 
Size: {Width=477, Height=321} 
PointToScreen(0,0): {X=0,Y=0} 

這一切都是關於邊界。

Answer 2

由於Uwe Keim和自己answer他question，我創建MoveForm函數計算偏移並正確設置格式的位置，無論Windows版本（即邊框大小）：

void MoveForm(Point p) // Move form to point 'p' 
    { 
     this.WindowState = FormWindowState.Normal; 
     this.Location = new Point(0, 0); 
     Rectangle rec = WindowHelper.GetWindowRectangle(this.Handle); 
     p.Offset(-rec.Location.X, -rec.Location.Y); 
     this.Location = p; 
    } 

MoveForm函數使用WindowHelper類從Uwe Keim的post：

public static class WindowHelper 
{ 
    // https://code.google.com/p/zscreen/source/browse/trunk/ZScreenLib/Global/GraphicsCore.cs?r=1349 

    /// <summary> 
    /// Get real window size, no matter whether Win XP, Win Vista, 7 or 8. 
    /// </summary> 
    public static Rectangle GetWindowRectangle(IntPtr handle) 
    { 
     if (Environment.OSVersion.Version.Major < 6) 
     { 
      return GetWindowRect(handle); 
     } 
     else 
     { 
      Rectangle rectangle; 
      return DWMWA_EXTENDED_FRAME_BOUNDS(handle, out rectangle) ? rectangle : GetWindowRect(handle); 
     } 
    } 

    [DllImport(@"dwmapi.dll")] 
    private static extern int DwmGetWindowAttribute(IntPtr hwnd, int dwAttribute, out Rect pvAttribute, int cbAttribute); 

    private enum Dwmwindowattribute 
    { 
     DwmwaExtendedFrameBounds = 9 
    } 

    [Serializable, StructLayout(LayoutKind.Sequential)] 
    private struct Rect 
    { 
     // ReSharper disable MemberCanBePrivate.Local 
     // ReSharper disable FieldCanBeMadeReadOnly.Local 
     public int Left; 
     public int Top; 
     public int Right; 
     public int Bottom; 
     // ReSharper restore FieldCanBeMadeReadOnly.Local 
     // ReSharper restore MemberCanBePrivate.Local 

     public Rectangle ToRectangle() 
     { 
      return Rectangle.FromLTRB(Left, Top, Right, Bottom); 
     } 
    } 

    private static bool DWMWA_EXTENDED_FRAME_BOUNDS(IntPtr handle, out Rectangle rectangle) 
    { 
     Rect rect; 
     var result = DwmGetWindowAttribute(handle, (int)Dwmwindowattribute.DwmwaExtendedFrameBounds, 
      out rect, Marshal.SizeOf(typeof(Rect))); 
     rectangle = rect.ToRectangle(); 
     return result >= 0; 
    } 

    [DllImport(@"user32.dll")] 
    [return: MarshalAs(UnmanagedType.Bool)] 
    private static extern bool GetWindowRect(IntPtr hWnd, out Rect lpRect); 

    private static Rectangle GetWindowRect(IntPtr handle) 
    { 
     Rect rect; 
     GetWindowRect(handle, out rect); 
     return rect.ToRectangle(); 
    } 
}